• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.736-736
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• 2012

유수의 침식과 퇴적작용은 지형의 변화를 일으키며, 이런 지형변화는 하천 흐름, 지하수 흐름 등의 변화를 가져오며 이는 다시 지형변화의 원인이 된다. 이런 일련의 과정이 되풀이되는 것을 지형발달이라 하며, 이는 수문 현상에도 지대한 영향을 미친다. 지형발달의 주요 인자에는 강우와 지반 융기 등이 있으며 각 주요 인자들은 복합적으로 지형발달에 영향을 준다. 하지만 지형발달 탐구 시 실제 지형을 대상으로 탐구하기에는 한계가 분명히 있다. 그래서 본 연구에서는 컴퓨터를 이용해 수식을 계산하여 수치적으로 지형발달을 모의하는 모형을 이용하여, 지형발달에 영향을 주는 강우와 지반 융기를 중점적으로 탐구하였다. 지형발달모형을 이용하면 더욱 다양한 관점에서 지형발달과정의 역동성을 파악하는 새로운 시도들이 가능하다. 특히 특정 환경 조건에서의 논리적인 지형의 반응을 통한 해석이 가능해져, 환경 변화로 어떠한 지형변화 또는 지표물질 수지 변화가 있을지를 예측할 수 있다(변종민, 2011). 또한, 지형발달 일련의 과정들을 살펴볼 수 있기 때문에 시 공간적 제약에서 벗어날 수 있다. 그러므로 지형발달모형은 강우와 융기 조건에 따른 지형발달을 모의하기에 적합하다. 본 연구는 LEGS을 이용하여 강우와 융기 조건에 따른 지형발달 모의를 진행하였다. LEGS는 지표수의 흐름을 탐색하는 방법으로 GD8을 이용한 물리 기반의 수치적 지형발달모형이다(Paik, 2012). 본 연구에서는 강우의 변동과 융기 조건의 변화가 지형발달에 상당한 영향을 미치는 것을 발견하였다. 특히, 유역의 표고차이 등과 같은 정량적인 지표의 변화에 주목하여 각종 분석을 하고, 물리적 원인을 고찰하였다.

• Journal of the Korean Geographical Society
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• v.46 no.3
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• pp.331-350
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• 2011

Advances in computer technology enabled us to simulate the integrated effects of various geomorphic processes on landscape evolution. This review introduces a theoretical framework for 2-dimensional numerical landscape evolution models (NLEMs) which have recently been used for various research purposes. In particular much attention is paid to the approaches deployed to model major geomorphic processes on a geological time scale in previous research. NLEMs can simulate landscape evolution by numerically solving the partial differential equation which represents the relationship among the geomorphic system components (GSCs). Simple process specifications of the relationships among GSCs on a long-term time scale in terms of quantification and attempts to combine processes represent the initial research on NLEMs. Later researchers have taken these simple NLEMs and elaborated on them. Introducing the theories of NLEMs in this review is expected to help researchers trying to utilize or develop NLEMs.

• Journal of the Korean Geographical Society
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• v.51 no.1
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• pp.77-88
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• 2016

Dramatic changes have so far been made in the system of central places over the past century. The development of transport has particularly exercised principal influences on the changes of the system of central places. This paper is to examine how and why the development of transport enables such changes to take place in the system of central places, through conducting model research. This paper suggests some models that development of transport be taken as an independent variable and that the division of market area between the central places be as the development of variable. The suggested models show that the development of transport extends the market area of higher central places but reduces the market area of lower central places.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.466-479
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• 2020

The purpose of this study was to explore the possibility of jobs for people with developmental disabilities in social farming and to derive job-creation plans. To this end, we analyzed the cases of social farms targeted for people with developmental disabilities among overseas social farming activities. And we visited and observed 5 social farms in Korea and interviewed the person in charge. The content of the study was to grasp the meaning and possibility of social farming as a job for people with developmental disabilities, and to explore ways to create a sustainable job for people with developmental disabilities in social farming. As a result of the study, social farming in Korea is in its infancy, and most of the activities are centered on agricultural experiences focused on healing and care for people with developmental disabilities. In the future, it was concluded that continuous agricultural education and activities are sufficient as suitable agricultural jobs for people with developmental disabilities. Based on these results, this study proposed a job model for people with developmental disabilities in social farming. The job model presented in this study is largely divided into a healing-oriented experience model, a care-oriented protective work model, and a social job model. In addition, a smart farm model and a plant factory model were added to the social job model.

• Journal of Gifted/Talented Education
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• v.22 no.2
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• pp.291-315
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• 2012

This study try to analyze feature of model creation and model developing process for gifted students and the activity of students and teachers affected those processes in scientific model constructing class for phase change of moon. For this, I teach scientific model constructing class for science gifted students. I shoot video and record the voice for whole class and each group activity, have a face-to-face talk for selected group members, analyze the paper of activities. I reconstruct model creation and model developing process for each groups and each students, draw a influence that activity aspects of the students and role of the teacher affected modelling process based on those data. After analyzing, I find that discussion in the group contribute model creation and model developing process and developing process of each model changed according to the similarity between target model and first model. The more the students actively participate group activities, the more first model is diversified and final model is more elaborated. Also, the teacher influence model creation and developing process.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.287-288
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• 2015

본 연구에서는 급증하는 청소년기 휴대폰 의존 문제의 심각성에 주목하여 우리나라 청소년들의 휴대폰 의존이 시간의 흐름에 따라 어떠한 변화 양상을 보이는지 실증적인 검증을 실시하고자 하였다. 이를 위하여 한국아동 청소년패널조사(KCYPS) 중학교 1학년 1~4차년도 자료에 대하여 이차잠재성장모형(second-order latent growth modeling)을 이용하여 휴대폰 의존의 발달궤적을 확인하였다. 휴대폰 의존의 발달궤적에 대한 최적의 모형을 찾기 위해 다수의 모형을 구성하여 비교 검증하였으며, 그 결과, 이차함수모형에 대하여 오차 간 공분산을 설정하고, 시간의 흐름에 따른 측정동일성 제약을 가한 후, 오차 간 공분산에 대한 동일화 제약을 가한 모형이 가장 좋은 적합도를 보이는 것으로 확인되었다. 이렇게 도출된 모형에 의하면, 중학교 1학년부터 고등학교 1학년까지 휴대폰 의존 정도는 증가하다가 그 증가율이 둔화되는 이차함수모형의 변화를 보이는 것으로 나타났다. 이러한 결과에 근거하여 청소년기 휴대폰 의존에 대한 예방 및 개입과 관련된 함의를 제시하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.281-281
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• 2017

하천에서 하도불안정(stream instability)으로 인하여 하상의 형태가 변화하고 하상파(sand wave)가 발생한다. 사련(ripple), 사구(dune) 등과 같은 하상파는 흐름저항을 유발하여 홍수시 수위를 증가시킨다. 수리실험 및 수치모형을 이용하여 사련 및 사구의 발달과정 그리고 이를 지나는 난류흐름에 대한 연구가 국외에서는 이루어지고 있지만 국내의 경우 거의 찾아보기 힘들다. 수치모형을 활용한 연구는 주로 횡방향으로 하상파가 일정하다는 가정하에 연직 2차원 수치모형을 적용하였으나 최근 컴퓨터 기술 및 수치기법의 고도화로 3차원 RANS(Reynolds averaged Navier-Stokes) 또는 LES(Large eddy simulation)를 이용한 수치모형이 개발되고 있다. 본 연구에서는 LES에 유사이송 및 하상변동 모형과 결합하여 사구발달에 대한 수치모의를 수행하였다. LES와 유사이송 및 하상변동 모형의 결합은 순간유속성분을 하상변동모형에 직접 적용되기 때문에 난류영향을 고려할 수 있는 것이 장점이다. 특히 사구의 발달에 따라 복잡한 흐름이 발생하며 3차원 와구조가 발생하므로 난류특성의 고려는 필수적이다. 수치모의는 Delft Hydraulics (Bakker et al., 1986)에서 수행한 수리실험 T39를 활용하였다. 수리실험은 길이 100 m, 폭 0.5 m 개수로에서 수행되었으며 평균유속은 0.611 m/s, 수심은 0.436 m이다. 하상파 실험에 사용된 유사입경은 0.78 mm 균일사를 사용하였다. 수치모의 조건은 수리실험과 동일하게 하였으나 계산시간의 효율을 고려하여 흐름방향의 계산영역은 4.0 m로 하고 주기경계조건(periodic boundary condition)을 부여하여 계산을 수행하였다. 수치모의 계산은 사구의 길이 및 파고가 평형상태에 이를 때까지 수행되었다. 수치모의 통해 사구발달에 따른 흐름 및 하상변동 특성을 분석하였다.

• The Korean Journal of Applied Statistics
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• v.33 no.2
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• pp.123-136
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• 2020

It is common to encounter correlated multiple outcomes measured on the same subject in various research fields. In developmental toxicity studies, presence of malformed pups and fetal weight are measured on the pregnant dams exposed to different levels of a toxic substance. Joint analysis of such two outcomes can result in more efficient inferences than separate models for each outcome. Most methods for joint modeling assume a normal distribution as random effects. However, in developmental toxicity studies, the response distributions may change irregularly in location and shape as the level of toxic substance changes, which may not be captured by a normal random effects model. Motivated by applications in developmental toxicity studies, we propose a Bayesian joint model for binary and continuous outcomes. In our model, we incorporate a skewed logit model for the binary outcome to allow the response distributions to have flexibly in both symmetric and asymmetric shapes on the toxic levels. We apply our proposed method to data from a developmental toxicity study of diethylhexyl phthalate.

• Journal of the Korean Geographical Society
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• v.46 no.6
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• pp.673-692
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• 2011

Advances in computer technology have enabled us to develop and use numerical landscape evolution models (NLEMs) for exploring the dynamics of geomorphic system from a variety of viewpoints which previously could have not been taken. However, as of yet there have been no trials using or developing NLEMs in Korea. The purpose of this research is to develop a 2 dimensional NLEM on a geological time scale and evaluate its usefulness. The newly developed NLEM (ND-NLEM) treats bedrock weathering as one of the major geomorphic processes and attempts to simulate the thickness of soil. As such it is possible to model the weathering-limited as well as the transport-limited environment on hillslopes. Moreover the ND-NLEM includes not only slow and continuous mass transport like soil creep, but also rapid and discrete mass transport like landslides. Bedrock incision is simulated in the ND-NLEM where fluvial transport capacity is large enough to move all channel bed loads, such that ND-NLEM can model the detachment-limited environment. Furthermore the ND-NLEM adopts the D-infinity algorithm when routing flows in the model domain, so it reduces distortion due to the use of the steepest descent slope flow direction algorithm. In the experiments to evaluate the usefulness of the ND-NLEM, characteristics of the channel network observed from the model results were similar to those of the case study area for comparison, and the hypsometry curve log during the experiment showed rational evidence of landscape evolution. Therefore, the ND-NLEM is shown to be useful for simulating landscape evolution on a geological time scale.

• Child Health Nursing Research
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• v.20 no.4
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• pp.350-358
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• 2014

Purpose: The purpose of this study was to define and clarify the concept of developmental care for preterm infants. Methods: The hybrid model method was used to identify the main attributes and indicators. In the field work stage, data were collected in Seoul and Cheonan, Korea. The participants were 5 nurses working in the NICU. Results: The concept of developmental care was found to have six attributes and ten indicators in 2 dimensions. For the nursing practice dimension, four attributes were derived. They were being like intrauterine state, individualization, interaction, and integrative care with awareness of development. For the family centeredness dimension, supporting parental attachment and professional alliance were attributes of developmental care. Conclusion: Developmental focused care can facilitate the identification of behavioral responses of newborns and provide individualized interventions for fostering growth and development. This concept analysis could provide guidelines for "developmental care" nursing practice and be useful for research in the neonatal field.